记关于 Lambda 表达式的基础写法

  1 namespace MyLambda
  2 {
  3     public delegate void Action<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, in T13, in T14, in T15, in T16, in T17>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12, T13 arg13, T14 arg14, T15 arg15, T16 arg16, T17 arg17);
  4     public delegate TResult Func<in T1, in T2, in T3, in T4, in T5, in T6, in T7, in T8, in T9, in T10, in T11, in T12, in T13, in T14, in T15, in T16, in T17, out TResult>(T1 arg1, T2 arg2, T3 arg3, T4 arg4, T5 arg5, T6 arg6, T7 arg7, T8 arg8, T9 arg9, T10 arg10, T11 arg11, T12 arg12, T13 arg13, T14 arg14, T15 arg15, T16 arg16, T17 arg17);
  5     public delegate void NoReturnNoParaOut();
  6
  7     public class LambdaShow
  8     {
  9
 10         public static void Show()
 11         {
 12             {
 13                 NoReturnWithPara method = new NoReturnWithPara(ShowStudent);//2 实例化委托 要求传递的方法必须和委托约束的签名一致
 14                 method.Invoke(196, "Emrys");//3 调用委托
 15             }
 16
 17             {
 18                 NoReturnWithPara method = ShowStudent;//实例化委托的时候，可以去掉 new NoReturnWithPara
 19                 method.Invoke(196, "Emrys");
 20             }
 21
 22             {
 23                 NoReturnWithPara method = delegate(int id, string name)//匿名方法
 24                 {
 25                     Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
 26                 };
 27                 method.Invoke(196, "Emrys");
 28             }
 29
 30             {
 31                 NoReturnWithPara method = (int id, string name) =>//lambda表达式  本质是一个匿名函数，是一个函数
 32                 {
 33                     Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
 34                 };
 35                 method.Invoke(196, "Emrys");
 36             }
 37
 38             {
 39                 NoReturnWithPara method = (id, name) =>//实例化委托 要求传递的方法必须和委托约束的签名一致   编译器会自动推断
 40                 {
 41                     Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
 42                 };
 43                 method.Invoke(196, "Emrys");
 44             }
 45
 46             {
 47                 //如果方法体只有一行，可以去掉大括号
 48                 NoReturnWithPara method = (id, name) => Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
 49                 method.Invoke(196, "Emrys");
 50             }
 51
 52             {
 53                 NoReturnNoPara method = () => { };
 54                 NoReturnWithOnePara method1 = i => Console.WriteLine(i);
 55                 method1.Invoke(13);
 56
 57             }
 58             {
 59                 WithReturnWithPara method = (m, n) => { return DateTime.Now.Second; };
 60                 Console.WriteLine("当前时间的second={0}", method.Invoke(3, 4));
 61             }
 62             {
 63                 WithReturnWithPara method = (m, n) => DateTime.Now.Second;
 64                 Console.WriteLine("当前时间的second={0}", method.Invoke(3, 4));
 65             }
 66
 67
 68             {
 69                 //0 到16个参数  无返回值 的泛型委托
 70                 Action method = () => { };
 71                 Action<int> act1 = i => Console.WriteLine(i);
 72                 Action<string> act2 = i => Console.WriteLine(i);
 73                 Action<string, long, DateTime, string, int, decimal, byte, LambdaShow, long, DateTime, string, int, decimal, byte, LambdaShow, Program> act1111 = null;
 74                 Action<string, string, long, DateTime, string, int, decimal, byte, LambdaShow, long, DateTime, string, int, decimal, byte, LambdaShow, Program> act11111 = null;
 75             }
 76             {
 77                 //0 到16个参数  带返回值 的泛型委托
 78                 Func<string> func1 = () => "????????Menzer";
 79                 Console.WriteLine(func1.Invoke());
 80                 Func<string, string, long, DateTime, string, int, decimal, byte, LambdaShow, long, DateTime, string, int, decimal, byte, LambdaShow, Program> func1111 = null;
 81                 Func<string, string, string, long, DateTime, string, int, decimal, byte, LambdaShow, long, DateTime, string, int, decimal, byte, LambdaShow, Program> func11112 = null;
 82             }
 83
 84
 85
 86
 87         }
 88
 89         public delegate void NoReturnNoPara();//1 声明委托
 90         public delegate void NoReturnWithOnePara(int id);
 91         public delegate void NoReturnWithOnePara1(string id);
 92         public delegate void NoReturnWithOnePara2(long id);
 93         public delegate void NoReturnWithOnePara3(DateTime id);
 94         public delegate void NoReturnWithPara(int id, string name);
 95         public delegate int WithReturnNoPara();
 96         public delegate int WithReturnWithPara(int x, int y);
 97
 98
 99
100
101         private static void ShowStudent(int id, string name)
102         {
103             Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
104         }
105         private static void ShowStudent1(int id, string name)
106         {
107             Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
108         }
109         private static void ShowStudent2(int id, string name)
110         {
111             Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
112         }
113         private static void ShowStudent3(int id, string name)
114         {
115             Console.WriteLine("id={0} name={1}正在高级班学习....", id, name);
116         }
117     }
118 }